SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4819f5760c3ac98c43945ae4fb769ed3f5494709502fab306755c474f8c8594d' 
  AND token = 'e+egyWraqP/5WfzifUBVOPGWhWDQfLuVLKZR7uxcJZ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}